The present invention relates to signal processing of electronic devices, and more particularly, to a method for performing active jammer suppression on an electronic device such as a Global Navigation Satellite System (GNSS) receiver, and to an associated apparatus.
One of the most important issues related to GNSS receivers is how to suppress interference. Typically, in a situation where GNSS signals are extremely weak, they can be below a noise level and are easily corrupted by interference. As a result, unrecoverable errors may occur in such a situation.
In particular, interference that comes from a harmonic frequency of a system clock (e.g. a CPU clock, or a pixel clock of a liquid crystal display module (LCM)) may fall within a GNSS band, causing in-band interference. According to the related art, a conventional passive suppression method that inserts a band-pass filter such as a surface acoustic wave (SAW) filter between an antenna and a low noise amplifier (LNA) of a GNSS receiver can only suppress out-of-band interference, rather than in-band interference.
Please note that adding the SAW filter does not help much on suppressing in-band interference since in-band interference often falls within a pass-band of the SAW filter. Thus, a novel method is required for suppressing in-band interference.